The present invention relates to a connector for joining the ends of two conduits which indicates when the conduits are properly connected and which prevents the breaking of the seal between the conduit ends should the connector become slightly loosened.
Devices for connecting the ends of two conduits so that fluid may be transmitted between the conduits without leakage are, of course, well known in the art. A typical example of such a connector is disclosed in French Patent 2 660 983 in which a thinner and deformed zone is formed in a threaded collar segment to assure tightening and self-locking of the connector within the collar.
However, when such a connector is used in aircraft engine applications, accidental loosening may take place because of the strong vibrations present in the engine, as well as the high and variable temperatures to which the engine is subjected. Such loosening cannot be tolerated in an aircraft engine environment, since a leak in the conduit connection can result in malfunction of the control, monitoring and/or the safety circuits. Also, if the conduit is conveying toxic or flammable fluid, the consequences of a leak in the connection can be catastrophic.
U.S. Pat. No. 3,325,192 discloses a connector having a tightness indicator projecting from the nut following deformation of the adjustment part during tightening. However, there is no assurance that this tightness indicator allows such an indication should the connection subsequently become loosened. Moreover, this disclosed connector does not provide for any means to retain the sealing connection in the event the connection becomes loosened. Thus, loosening of the connector quite possibly will result in leakage of fluid from the connection.
French Patent 2 421 300 discloses a connector device for affixing a wheel to a vehicle hub by a bolt or a nut, wherein the connection includes an axially elastic washer inserted between the bolt head and the wheel having at least one external axial projection projecting in the direction opposite of the bolt and nut displacement caused by tightening. The axial projection comprises an end element nesting in the bolt or nut when the axial flattening of the washer corresponds to the desired tightening force. The deformation and partial destruction of the washer prevents the wheel from coming off. However, this patent does not disclose the use of such a washer in a conduit connector.
Thus, it is desirable that aircraft conduit connectors be equipped with a device for precluding the loosening of the connectors and to further ensure that the sealing fit between the conduit ends is not breached should the connector become slightly loosened.